Sven,
I discovered that there were 4 logged dives that caused the error. #11, 60, 67, and 70. When I skipped these dives, it uploaded successfully. I hope this helps as you continue the tedious debugging process. Please let me know if I can test anything else.

Thank you, I was able to reproduce the error and think I know already the reason. I'll have to do some more testing and I'm sure I have a fix with the next update in a few days. In the meantime the UDCF export and upload should work.